Collar fastener



FIG. 1 is a perspective view of a collar fastener showing my new design, the broken lines forming no part of the claimed design;

FIG. 2 is a right side elevational view of the same, the broken lines forming no part of the claimed design;

FIG. 3 is a left side elevational view of the same, the broken lines forming no part of the claimed design;

FIG. 4 is a bottom view of the same;

FIG. 5 is a top view of the same;

FIG. 6 is a front view of the same, the broken lines forming no part of the claimed design;

FIG. 7 is a back view of the same; and,

FIG. 8 is perspective view of the collar fastener including (1) an exemplary collar having means for securing the collar to the collar fastener, and (2) an exemplary tag attached to the front of the collar fastener, whereby the broken lines of the collar fastener, collar and tag form no part of the claimed design. 

The ornamental design for a collar fastener, as shown and described. 